1. Field of the Invention
The invention relates to a system for automatic correction of the color balance of the signals which control color and luminosity of color television picture. In this system, when a prespecified luminosity gradation in the color television picture is detected and when at the same time the chroma-saturation drops or remains below a prespecified chroma-saturation threshold, a hue of the television picture prevailing at this moment is stored. A function of the stored hue is used to derive control signals which regulate a device known per se for color correction in such a way that a chromatic aberration in the color balance of the signals that control color and luminosity of a color television picture is reduced.
2. Description of the Prior Art
It has been observed that certain picture patterns afflicted with a color stain are faultily corrected in the system disclosed in my prior application U.S. Ser. No. 620,409, filed Oct. 7, 1975. In such picture patterns, the color stain is not uniformly distributed over the picture surface. In some picture areas, the chroma-saturation of the color stain is above the set threshold of a chroma-saturation threshold detector, and in other picture areas below this threshold. According to the main patent the color correction would first operate in the picture areas wherein the chroma-saturation is below the set chroma-saturation threshold. Thus, the previously more strongly saturated picture areas would be brought into the lower chroma-saturation threshold area. More strongly saturated colors in the picture pattern would therefore be undesiredly corrected and desaturated in color.